Hello@mashreq ,

Thanks for contacting our community.

If you forgot the Wi-Fi password for the modem router.
    1. Check the bottom label of the router for the default Wi-Fi password, which is typically an 8-digit number.
    2. Open the Tether App, log into the router under Devices, and navigate to Tools > Wireless to view the Wi-Fi password.
    3. Connect your computer to the modem router via Ethernet, access tplinkmodem.net, and find the password under Advanced > Wireless > Wireless Settings.
    4. If all else fails, reset the modem router and use the default Wi-Fi password to reconnect. 
Note: A hard reset will revert the router to its factory settings without Internet access, requiring reconfiguration.